Magnetic Behavior of Mechanically Milled FeNi-CoO Nanocomposites
| Autor: | Sanjay R. Mishra, I. Dubenko, K. Marasinghe, S. Roy, N. Ali, Joseph Losby |
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| Rok vydání: | 2004 |
| Předmět: |
Materials science
Condensed matter physics Coercivity Magnetic hysteresis Electronic Optical and Magnetic Materials Condensed Matter::Materials Science Hysteresis Nuclear magnetic resonance Exchange bias Ferromagnetism Antiferromagnetism Magnetic nanoparticles Condensed Matter::Strongly Correlated Electrons Electrical and Electronic Engineering Néel temperature |
| Zdroj: | IEEE Transactions on Magnetics. 40:2716-2720 |
| ISSN: | 0018-9464 |
| DOI: | 10.1109/tmag.2004.830227 |
| Popis: | The effects of crystallite size and ball-mill-induced defects on the magnetic properties of ferromagnetic (FM) FeNi-antiferromagnetic (AFM) CoO (Neel Temperature=290 K) nanocomposites are assessed by magnetic measurements. Asymmetric zero-field-cooled (ZFC) hysteresis loops were observed for samples milled for 30h and longer. The field-cooled (FC) hysteresis loops were asymmetric and shifted in the direction opposite to the cooling field. The enhancement of coercivity and squareness ratio (M/sub R//M/sub S/), along with a presence of a loop shift after field cooling indicates the presence of an exchange bias effect between the FM and AFM phases of the composite. The exchange bias field extracted from the 5 K FC measurement shows continuous enhancement with milling times up to 30 hours and a reduction upon prolonged milling. The temperature dependent exchange bias field measurement shows that the exchange bias field reduces to zero at temperature T |
| Databáze: | OpenAIRE |
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